Mine trap-door



2 Sheets-Sheet 1.

- (No Model.)

. G. J. HERTH.

MINE TRAP DOOR.

No. 541,048. Patented June 11, 1895.

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G. J. HERTH.

MINE TRAP DOOR.

'Patenfied June 11, 1895.

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2 Sheets-Sheet 2.

mvantoz E STATES QFFI.

GEORGE J. HERTH, OF EVANSVI'LLE, ASSIGNOR TO THE AUTOMATIC MINE DOOR OOMPANY, OF TERRE HAUTE, INDIANA.

MINE TRAP-DOOR.

$PEGIFICATION forming part of Letters Patent No. 541,048, dated June 11, 1895.

I Application filed August 18, 1894- To aZZ whom it may concern: Be it known that I, GEORGE J. HERTH, a citi-- zen of. the United States, residing at'Evansville, in the county of Vanderburg and State of Indiana, have invented certain new and useful Improvements in Mine Trap- Doors; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art IO to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form'a part of this specification.

r5 My invention relates to new and useful improvements in mine trap-doors, andto one of thatclass which is adapted to control or cut off air currents from the different entries or rooms, and which is automatically opened and closed bya car passing through the entry on a track in eitherdi'rection, the door'being opened just before the car or cars reach the door and closed immediately after the car or cars have passed through such door.

In the drawings, Figure l is a perspective View of my improved trap-door and its operating mechanism, the door being closed. Fig. 2 is a similar View, the operating mechanism on the right-hand side of the door being 0 broken away and the mechanism on the lefthand shown in the position in which it is held by a car passing through the door from the left, the door being open. Fig. 3 is a longitudinal sectional View through thebarrel 5 which carries the spring for closing the door, its construction and connections being shown. Fig. 4 is a detail under side perspective view showing the manner of connecting the trip and its lever together.

In detail, 1 represents a frame work'su'pported across the track in the entry of a mine,

the inner end 2 of such frame usually extending into a recess, cut, out in the wall of the entry for its reception, the mine trap door 3 5 also adapted to be pushed back into such recess when opened.-

The door 3 has hangers on its top in which are carried wheels which run on a horizontal track t on the upper cross-piece of the frame work 1.

- 5 is a shaftor rod having hearings in boxes Serial No. 520,654. (No model.)

6 secured to the cross-ties 7 on one side of the track 8 and parallel with the same, the shaft 5extending under the doorand preferably about ten feet on each side of the same. To this shaft on one side of the door is rigidly secured an operating lever 9, its upper end having pivoted to it the link 10 which is in turn pivoted to the door 3 in any desired manner.

Just beyond the outer box 6 at each end of the shaft 5 is rigidly secured to each end of such shaft and in line with the door operating lever 9, a crank 11 whose upper end is pivoted to a link 12,,the outer end of such link being pivoted in turn to a horizontal le- 'ver 13, pivoted or loosely mounted on a pintle secured to the top of a suitably-supported base-plate 14. Also'loosely mounted on such pintle is a trip arm 15 which is normally held at right angles to the track by a spring 16 secured to the lever and any desirable fixed point (an overhanging arm being in this instance shown) the end of the trip arm 15 projecting far enoughto be in the path of passing cars, and a wheel 17 being mounted in the bifurcated end of such trip arm.

7 The trip arm 15 is adapted to be connected with the lever 13 through a lug 18 on such trip arm and a slot or recess 19 in the lever 13, the lug at certain points engaging with the ends of such slot. A link 31 also connects the trip arm 15 and the lever 13 together, the link being pivoted to the trip arm or a bracket 32 formed thereon. The other end of the link is provided 'witha slot 33 through which a pin 3% passes, it also passing through the bracket 35 formed on the lever 13. T'ne office of the link connection is to strengthen and brace both the lever and the trip arm, and take the strain off of each at their piv- 9o otal point.

Adjacent to the trap door and on each side thereof is pivoted to any suitable support or bracket 20, a pivoted arm 21 which is connected to the trip arm 15 on its side of the door by a rod or link 22 each of the arms 21 having a wheel or roller 17 in its outer end similar to those in the'trip arms 15, and the ends of the trip arms and arms 21 are in the same line with relation to the track.

23 is a barrel or cylindrical casing secured by brackets 24 to the upper cross-piece of the 'frame 1, from which. the trap door 3 is supported, the casing 23 being outside of the track 4 upon which the door wheels run and parallel with such track.

25 is a screw cap secured to the inner end of the casing or barrel 23 and through a central hole or opening in the cap 25 passes a rod 26 which is about the same length as the casing and has on its end within the casing the button or heat 27 which just fits the barrel 23. Between the head 27 and the cap 25 on the inside of the barrel 23 there is coiled around the rod 26 a spring 28 the space between the rod and the inside of the barrel being just enough to allow the spring to work freely therein, but close enough to prevent its buckling. The end of the rod 26 which extends outside of the barrel 23 is secured in any suitable manner to a bracket 29 attached to the trap door 3 near its top, the object of the rod and spring being to close the door aftera car or cars have passed through it.

Having mentioned in detail the several parts of my device I will now describe its operation which is as follows: The door and the tripping mechanism on each side thereof being in the position shown in Fig. 1, we will suppose a car or a number of cars to approach from either direction drawn by a mule as they usually are. \Vhen the first ear reaches the outer or trip arm and comes in contact with the same, the mule or other animal will not have quite reached the door and as the car continues on, the door will be immediately opened as at the first movement of the trip arm 15, it will through its connection with the lever 13 (the pin 18 of the trip arm 15 being against the inner end of the slot or recess 19 on the lever 13, and the pin 31 of the trip arm being against the inner end of the slot 33 of the link 31 which connects the trip arm and lever together), turn the same, and it through the link 12 will exert its force on the crank 10 which will turn the rod or shaft 5 which through the operating lever 9 will open the door. As the door is being thus opened, the spring 29 coiled around the rod 27 in the barrel 24. will be compressed. The inner arm 21 will be moved simultaneously with the outer trip arm through the rod or link 22 connecting the two together, and as the car or cars more along, the wheels in the ends of such arms will turn or roll on the sides of the car or cars. \Vhen the front end of the car or cars has passed through the door and the rear of the car or last car is about to pass through, the rear end of such car will still contact with the wheel of the pivoted arm 21 until the car is practically through the door when it passes from contact with such wheel and thereby releases the entire tripping mechanism. The spring 16 on that side of the door will draw the arms 15 and 21 back to their normal position at right angles to the track and at the same time the coiled spring 29 will exert its greatest strength and start to close the door behind the car which has passed through, the spring gradually lessening its tension as the door closes so there will be little or no jar when the door closes completely, and yet the tension of the spring will be sufficient to hold it securely closed.

It will be understood that as the cars pass through the trap door from one side they will contact with the wheels in the end of the arms on the farther side moving them outward or away from the door, and yet not affecting the tripping mechanism in any way. This is explained in this way: The slot or recess 19 in each of the levers 13 is sufficiently long so that when the arms on one side of the door are operated, while the arms on the other side of the door are still in their normal position. the ing or projection 18 on the outer one will be in the middle of the slot or recess and when the second arms are operated by contact with the moving car, the lug 18 will be moved to near the outer end of the slot or recess 19 so that when the car releases its contact on the first pair of arms the door can close and the parts of the second tripping mechanism will be in such position that when the car ceases contact on such second arms the ing 18 on the outer one will be brought back to its normal position by the spring 16, and will just touch the inner end of the recess or slot 1!) so that the parts will again be in the position shown in Fig. 1, and ready to he again operated by a car or cars coming from either direction.

My trap door has numerous ad vantages, the principal one being economy in space as the outer or trip arms only require to be set down ten or fifteen feet from the door on each side or a little more than the length of a mule or other animal used to pull the cars, whilein most doors heretofore used the trips were required to be set a distance on each side of the door equal to the longest train which was to pass through it. This matter of space is a great item in mines where many entries are on curves or there is an angle or sharp turn very near the door. A much cheaper door is also made and one that can be made and set up regardless of how many cars there are in the trains which are to run through it. It will always work perfectly there being no parts to get out of order, nor any long shafting. The tripping mechanism is entirely above ground and therefore not affected by water which is usually found in mines. The spring mechanism for closing the door is simple in construction,am ply protected by its surrounding casing and its operation is perfect, it exerting the most force when starting to close the door, and less force as the door is closed,

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so that there are no jars or jolts which in parts of the tion, strong and durable and perfect in operation..

It is obvious that changes may be made in its construction and use without departing from the spirit or principle of my invention, for weights can be used to bring the trip arms back to their normal positions at right angles to the track, and many other changes can be made as well.

Y Having fully described my invention, What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a trip for mine trap-doors a pair of arms pivoted on the same side of the door at the side of and lying normally at right angles to the track, theirends connected together and in the path of passing cars and mechanism between such arms and the door whereby when they are moved in one direction through such mechanism they open the door, substantially as set forth. 7

2. In a trip for'mine trap-doors a pair of arms suitably pivoted on the same side of the door, at the side of and lying normally at right angles to the track, their ends connected together and in the path of passing cars, mechanism connecting the arms with such door wh reby when said arms are moved in one direction they open said door, and a spring connected with such door for closing it, substantially as set forth.

3. In a trip for mine trap-doors, a pair of arms suitably pivoted on the same side of the door at the side of and lying normallyfat. right angles to the track their outer ends connected together and carrying wheels which are in the path of passing cars, a similar pair of arms pivoted on the other side of said door, mechanism connecting each pair of the arms with such door, whereby when the trip arms on either side 'of the door are moved in one direction the door will be opened, and a spring connected to suchdoor for closing it.

4:. In a trip for mine trap-doors, a pair of arms suitably pivoted on the same side of the door at the side of and lying normally at right angles to the track, their ends connected together and in the path of passing cars, a similar pair of arms pivoted on the other side of said door,mechanism connecting such arms on each side of the door with such door whereby when the said trip arms are moved-in one direction they open said door, a rod connected with the door and working in a barrel connected with the door frame and a spring coiled around such rod for closing the door, substantially as set forth.

5. In a trip for mine trap doors, a pair of arms loosely pivoted at suitable points on thesame side of the door at the side of and normally lying at right angles to the track, their ends connected together and in the path of passing cars, a lever loosely mounted on the pivot pin or pintle of the outer or trip arm, such lever adapted at a certain point to be operated by the trip arm, mechanism connecting the door with such lever whereby the door may be opened, and a spring device for closing such door, substantially as set forth.

6. A trip for mine trap doors consisting of a trip arm loosely mounted on a pin or pintle at a suitable distance at the side of the door, and in the path of passing cars, a lever loosely mounted on such pin or pintle, a recess formed in such lever near its pivotal point, a lug on the trip arm working in such recess, a link pivoted to said trip arm and to the lever through a slot in such link at a distance from their pivotal points whereby on the movement of the trip arms in one direction, the lever will be operated, but on' the moving of the trip arm in the other direction the lever will remain stationary.

In testimonywhereot I aflix my signature I in presence of two witnesses. 

